25 lines
771 B
Plaintext
25 lines
771 B
Plaintext
export default function negateValue(value) {
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value = `${value}`
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if (value === '0') {
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return '0'
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}
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// Flip sign of numbers
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if (/^[+-]?(\d+|\d*\.\d+)(e[+-]?\d+)?(%|\w+)?$/.test(value)) {
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return value.replace(/^[+-]?/, (sign) => (sign === '-' ? '' : '-'))
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}
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// What functions we support negating numeric values for
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// var() isn't inherently a numeric function but we support it anyway
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// The trigonometric functions are omitted because you'll need to use calc(…) with them _anyway_
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// to produce generally useful results and that will be covered already
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let numericFunctions = ['var', 'calc', 'min', 'max', 'clamp']
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for (const fn of numericFunctions) {
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if (value.includes(`${fn}(`)) {
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return `calc(${value} * -1)`
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}
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}
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}
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